Insulation and insulation systems may be utilized to provide thermal and/or acoustical insulation in a variety of applications for homes, buildings and other structures, piping and duct work, aircraft, watercraft and the like. In aircraft, insulation is typically installed to aircraft interior surface structures, subcomponents and subsystems in order to protect occupants, cargo, and equipment, as well as the aircraft structural components from thermal and acoustic extremes and adverse environmental conditions and noise associated with engine operation, mechanical vibration and high velocity air flow.
In a medium sized aircraft, there may be as many as 500 insulation applications; and even more in the largest of aircraft. Amongst the primary applications areas are passenger and cargo compartments, and may further be applied in other compartments and components such as to environmental control systems, water and waste systems or any other area where thermal and/or acoustical protection is desired or required.
Commercial and other aircraft may experience extremely high moisture condensation and associated water leakage through overhead panels due to a phenomena commonly referred to in the commercial airplane industry as “Rain-in-the-Plane.” This problem originates moisture contributions from various sources, including the environmental control systems, conditioned air duct distribution systems, internal-external temperature differentials, and passenger breathing. It is the most severe in aircraft operated in high humidity conditions or in tropical climates. When released, the condensate often affects electrical systems housed behind and on ceiling panels, can cause corrosion and shorten aircraft useful life. Damaged electrical systems can cause equipment failure and dangerous operational malfunctions, requiring equipment repair and replacement or initiation of in flight emergency landing procedures, such as fuel dumping and premature landings at the nearest available airport. The negative affects of condensed moisture in aircraft and related emergency measures can result in significant economic losses due to costs associated with fuel dumping, lost flight time due to grounding of out-of-service aircraft, passenger discomfort, inconvenience and lack of confidence, and required systems analyses and repairs. These losses are currently being incurred by the commercial airplane industry with the use of conventional insulation systems.
Insulation systems or assemblies utilized in aircraft are commonly referred to as “blankets.” An example of a prior art insulation blanket 10 is illustrated in FIG. 1. Prior art insulation blanket 10 is typically of a generally rectangular or square shape and is formed of an insulating batting 12 disposed between a cover 14, usually two plastic or polymeric sheets 16. The perimeter edges 18 of sheets 16 of prior art blanket 10 are sealed or joined together with tape or heat sealed. Prior art blanket 10 may also be provided with breathers such as the prior art breather 20 shown in FIG. 2. FIG. 2 is a fragmentary, plan view of prior art blanket 10. Breather 20 is a window cut into the blanket cover 14 through one of the sheets 16 over which an open weave or screen material 22 is applied and affixed with strips of tape 24. Breathers allow air, gases and moisture to pass into and out of the blanket. Without breathers, some insulation blankets may balloon and possibly rupture. Batting 12 is typically a non-woven material formed of loose, compressible fibers, such as materials generically referred to as fiberglass.
Batting 12 is prone to shifting within prior art blanket 10 after installation over a period of use due to gravitational, vibrational and impact forces and can cause bulking or gathering at the lowest point of prior art blanket 10 when attached to a vertical or arcuate surface. With respect to an arcuate surface, prior art blanket 10 and the surface are typically not in constant interface, meaning that prior art blanket 10 does not completely conform to the shape of the surface when installed. This can also be a problem on vertical and horizontal surfaces to which insulating blankets are improperly installed without attention to assuring that the blanket and surface are in constant interface. Such improper installation may reduce the effectiveness of the insulation. Further, it may result in “pockets” or “pocketing” where moisture accumulated within the blanket or its batting may pool or in pooling of condensate between the blanket and the horizontal or arcuate surface. Insulation blankets applied with a constant interface provide desirable insulation performance; however, most prior art insulation blankets are typically installed without a constant interface. A “constant interface” is understood to mean that a blanket generally conforms to the surface to which it is installed without pocketing and with minimal to no space between the surface of the blanket and the surface of the structure to which it is applied or installed. Bulking, pocketing and pooling negatively impact the thermal and/or acoustical performance of the blanket and may promote Rain-in-the-Plane.
There are a significant number of different aircraft designs and models and an equally significant, if not greater, variety of potential insulation applications, individual components and locations, in aircraft. Insulation blankets are developed, sized, and formed in a number of standard sizes for individual aircraft components and locations. This requires preparation of preliminary detailed designs from which cover sheet and batting templates are developed for the various components and locations for a variety of different aircraft. For purposes of illustration and context, in a medium sized aircraft, there are approximately 500 different blanket sizes requiring 1500 templates. Templates are then used as patterns to fabricate blankets sized and shaped for the large number of individual component and locations. This results in a large inventory of different sized blankets for different aircraft models and designs that must be stored or stockpiled on hand for installation in aircraft under assembly.
Even with such a stockpile of standardized blankets, there remain a number of applications for which these prior art blankets are not a good fit. Such applications require, extensive reworking of the blankets. For the reworking, aircraft assembly workers have to cut and size the blankets, and to seal the cut perimeter edge or edges in order to contain the batting within the blanket. Sealing can involve folding of the edges along with sewing, taping, heat sealing or combinations of these steps. This is not only a labor intensive effort, but an inefficient fix, both in terms of blanket integrity and performance, as well as in time and expense. Further, it exposes the workers to contact with the batting fibers. Excessive handling of and contact with batting material can result in skin contact with the fibers and cause shedding of fibers which can be come airborne. Exposure to batting fibers is known to have the potential for deleterious human health effects, such as skin irritations (e.g., swelling, break-out, and rush) and negative respirator and breathing impacts.
Installation methods for prior art insulation blankets in aircraft are labor intensive, requiring expensive hardware and long set-up times to position blankets, identify tie-points, mark attachment points, coordinate mating points with stand-offs, apply the stand-offs (typically with adhesives), cure adhesives, and provide breathers or breathing systems. Insulation blanket retentions systems some times require punching, puncturing, piercing and/or darting through the body of the blanket in order to provide proper mating or attachment points with stand-offs and fasteners. Prior art blankets can be heavy and cumbersome, making for difficult handling. Despite best efforts, prior art installation methods are susceptible to error and to inconsistencies which can lead to the pocketing problems previously mentioned. Customizing to unique customer aircraft components, inconsistent draping of insulation blankets around curvatures, inadequate tension, failure to provide constant interfaces and the like also contribute to installation errors and pocketing.
In FIG. 3, a section of duct 26 (shown in partially, cross-sectional view) insulated with prior art blanket 10 is shown. Typically, this prior art blanket is assembled at the time of installation typically by applying batting 12, securing batting 12 with tape or fiberglass cord 27 (as shown) in order to hold or stabilize batting 12 in place and avoid to avoid shifting, and covering the batting with sheet 16. Optionally, prior to applying batting 12, a sheet 16 may be first secured to duct 26 as is shown in FIG. 3; of course, the addition of sheet 16 prior to applying batting 12, represents an additional installation step with associated materials and labor costs. Adhesives applied to the exterior surface of a duct 26 prior to covering with the surface with prior art blanket 10 may require surface preparation and curing time. Typically, as can be seen in FIG. 3, when insulating ducts and pipes, large spaces have to be left uncovered and unprotected by the blanket 10 in order to provide a surface of sufficient size to secure the perimeter edge 18 of blanket 10 with tape 24, bead clamps and the like. In FIG. 3, such a bear space can be seen to the left with the perimeter edge 18 of cover 14, where no batting is present, secured over such the bear space with tape 28. This essentially results in a space with minimal to no effective insulation. An even greater space is needed between adjacent prior art blanket sections on a length of pipe or duct, resulting in reduced or less than optimal insulation.
The foregoing is not an exhaustive listing of the disadvantages of prior art insulation blankets and installation methods but due represent some of the more significant shortcomings and deficiencies of the prior art. It would be desirable to provide insulation blankets and retentions systems that overcome some, all or various combinations of the shortcomings and deficiencies of the prior art.
Applicants have developed modularized installation and retentions systems the various embodiments of which overcome some, all or various combinations of the above-noted shortcomings and deficiencies of the prior art.